News of Promising Cancer Drugs Lifts EntreMed Stock
High-profile publicity about a promising treatment for cancer triggered a speculative frenzy for EntreMed Inc.’s stock Monday. But as the biotechnology company’s shares more than quadrupled in value, experts weighed in to discourage the notion that a cure is just around the corner.
EntreMed’s shares briefly touched $85 before closing the trading day at $51.94, gaining $39.75 on Nasdaq and giving the company a market capitalization of $641 million. EntreMed’s stock caught fire following a glowing report about the prospects for the Rockville, Md.-based company’s two new anti-cancer agents in Sunday’s New York Times.
The compounds have so far been tested only in mice, in which they seem to be able to cure many kinds of cancer. However, many experimental treatments that work in mice do not have the desired effect in humans.
EntreMed’s executives awoke Monday to a worldwide media storm. They found themselves walking a tightrope, simultaneously talking up the potential of their research and trying to play down expectations that it will pay off immediately.
“We’re concerned because a lot of statements are being made that are very misleading to cancer patients,” EntreMed spokeswoman Mary Sundeen said. “These results that have come out in the mice are incredible. But we don’t know if these compounds will have any effect whatsoever in human beings.”
In a statement prompted by the frenzy, the National Cancer Institute, which is working closely with EntreMed, said it was “encouraged” by animal studies of Angiostatin and Endostatin and had “made it a high priority to move research forward on these compounds.” But the cancer institute added, “It is very important to emphasize that while the possibilities raised by these studies in mice are encouraging, it is not known whether Endostatin or Angiostatin will be effective in people with cancer.”
In the best case, the compounds in question are not likely to enter human trials for another year or more, and even if the tests go well, it could be several years before they are licensed for use by the public.
EntreMed, which employs about 50 people, is a leader in a field that many scientists believe is among the most promising in cancer research: drugs that would starve tumors to death by blocking the growth of the blood vessels they need to expand.
The same developing body of knowledge may allow doctors to prevent a leading cause of blindness. But in that instance too, much work remains to be done before drugs go on sale.
EntreMed was founded seven years ago in part to commercialize the work of Judah Folkman, a Harvard University researcher. He and his associates have spent decades studying the importance of blood vessel formation and other diseases, including macular degeneration, an eye disease that can cause blindness.
But only in recent years have scientists learned enough about the inner workings of cells and developed tools that can begin to manipulate blood vessel development.
In healthy adults, new blood vessels grow only under rare circumstances--during pregnancy, for instance, or when a wound is healing. But the formation of new vessels seems to be a fundamental element in the progress of several diseases.
Folkman has long theorized that cancers can’t grow any bigger than a pea until they trick the body into growing new blood vessels. They do this by making proteins the body recognizes as signals to form the vessels. The vessels grow toward the tumor, supplying it with oxygen and nutrients and allowing it to grow to the point that it threatens the life of the patient.
A worldwide research effort is now focused on finding chemicals that can switch off these signals.
New blood vessel formation is known to scientists as angiogenesis, and compounds that block it are known as angiogenesis inhibitors. In theory, because an adult who isn’t pregnant rarely needs to grow new blood vessels, these compounds should be able to work without the nasty side effects now seen in conventional cancer treatments. In macular degeneration, they might prevent the excessive growth of blood vessels that cloud the eyes.
Some of the most recent, and most exciting, research from Folkman’s laboratory is based on the strange fact that tumors themselves, once they are adequately supplied with blood, sometimes produce substances that block blood vessel formation. In this way, a primary tumor suppresses the formation of secondary tumors that might compete with it for nutrients. As EntreMed Chief Executive John Holaday said, the first tumor “plays king of the hill.”
